給連結吧，這是個直接使用pcm資料來繪製圖形.

http://stackoverflow.com/questions/8325241/android-audio-fft-to-display-fundamental-frequency?rq=1 

關鍵程式碼貼出來吧:

/Conversion from short to doubledouble[] micBufferData =newdouble[bufferSizeInBytes];//size may need to changefinalint bytesPerSample =2;// As it is 16bit PCMfinaldouble amplification 
 
=1.0;// choose a number as you likefor(int index =0, floatIndex =0; index < bufferSizeInBytes - bytesPerSample +1; index += bytesPerSample, floatIndex++){double sample =0;for(int b =0; b < bytesPerSample; b++){int v = audioData[index + b];if(b < bytesPerSample -1|| bytesPerSample ==1){
                v 
 
&=0xFF;}
            sample += v <<(b *8);}double sample32 = amplification *(sample /32768.0);
        micBufferData[floatIndex]= sample32;}

 很有意思，這個事聲道16位的繪製.

                   1 由於是單聲道所以直接去這2個8位的資料哦(bytesPerSample = 2),sample就是振幅的值哦

                   2 振幅的運算，由於是16位的，所以我們要知道，前八位（一個byte）就是低位的（是這樣定義的哦）,